Turbine Nozzle Segment, Turbine Nozzle, Turbine, and Gas Turbine Engine

ABSTRACT

A turbine nozzle segment, a turbine nozzle, a turbine, and a gas turbine engine. The turbine nozzle segment is provided with an outer band  39  of an arc shape, an inner band  41  of an arc shape, a thick stator vane  43  in which an insertion hole  49  to which a probe  47  is insertable from a side of the outer band  39  is formed and on the pressure surface  43   b  of which an inlet hole 51 communicating with the insertion hole  49  is formed, and a thin stator vane  45  having a suction surface  45   a  having an identical shape to a suction surface  43   a  of the thick stator vane  43  and a smooth pressure surface  45   b  approximating to a pressure surface  43   b  of the thick stator vane  43  configured to be thinner than the thick stator vane.

TECHNICAL FIELD

The present invention relates to a turbine nozzle segment, a turbinenozzle, a turbine, and a gas turbine engine.

BACKGROUND ART

It is generally carried out to measure temperature and pressure of a hotgas at the vicinity of an inlet of a low pressure turbine and control afuel flow rate and such based on the measured data in a case of gasturbine engine such as a jet engine. There may be a case to apply aconfiguration to the gas turbine engine to measure the temperature andthe pressure of the hot gas at the vicinity of the inlet of the lowpressure turbine as for an example.

More specifically, rakes are arranged extending in radial directions ofthe gas turbine engine at the vicinity of the inlet of the low pressureturbine in a gas flow path of the gas turbine engine Moreover, in eachof the rakes, an insertion hole is formed so that a probe for measuringthe temperature or the pressure of the hot gas can be insertedtherethrough, and an inlet hole communicating the insertion hole isformed at a side face of the rake. The probe is linked with a controllerfor controlling the fuel flow rate and such via an amplifier.

Therefore, in the course of operating the gas turbine engine, thetemperature or the pressure of the hot gas flowing into the inlet holeis measured by means of the probe inserted into the insertion hole Then,the controller controls the fuel flow rate and such based on themeasured data inputted from the probe via the amplifier

DISCLOSURE OF INVENTION

By the way, if the rakes extending in the radial directions are arrangedat the vicinity of the inlet of the low pressure turbine in the gas flowpath, the axial length of the gas turbine engine is elongated, and itbrings about weight increase of the gas turbine engine, in addition, therakes in the gas flow path come to be vibration excitation source andair resistance, thereby it gives rise to a problem of decline in theengine performance of the gas turbine engine.

On the other hand, it could be considered to shape a stator vane of alow pressure turbine nozzle applied to the low pressure turbine into ahollow structure by casting and insert the probe into the Interior ofthe stator vane, however, the low pressure turbine nozzle is segmentedinto a plurality of turbine nozzle segments and it is technicallydifficult to shape the stator vane as a part of the turbine nozzlesegments into a hollow structure by casting, and there is a problem thata production cost of the turbine nozzle segments in other words, aproduction cost of the turbine nozzle, becomes very high.

Therefore, to solve the aforementioned problem, a first feature of thepresent invention is, a turbine nozzle applied to a turbine of a gasturbine engine, the turbine nozzle comprising a plurality of turbinenozzle segments arranged in a circle: each of the turbine nozzlesegments comprising; an outer band of an arc shape, an inner band of anarc shape provided to opposed to the outer band, a thick stator vaneintegrally formed to link between the outer band and the inner band, anda thin stator vane integrally formed to link between the outer band andthe inner band, the thin stator vane having a suction surface having anidentical shape to a suction surface of the thick stator vane and asmooth pressure surface approximating to a pressure surface of the thickstator vane, the thin stator vane being configured to be thinner thanthe thick stator vane so that the pressure surface comes near to thesuction surfaces, in that; an insertion hole to which a probe formeasuring a temperature or a pressure of a hot gas is insertable from aside of the outer band is formed in the thick stator vane of any turbinenozzle segment of the plurality of turbine nozzle segments, and an inlethole communicating with the insertion hole is formed on the pressuresurface of the thick stator vane of said any turbine nozzle segment.

further, a feature of the present invention is a turbine nozzle segmentas a segment of a turbine nozzle applied to a turbine of a gas turbineengine, the turbine nozzle segment characterized by comprising an outerband of an arc shape; an inner band of an arc shape provided to opposedto the outer band, a thick stator vane integrally formed to link betweenthe outer band and the inner band, wherein an insertion hole to which aprobe for measuring a temperature or a pressure of a hot gas isinsertable from a side of the outer band is formed in the thick statorvane, and an inlet hole communicating with the insertion hole is formedon the pressure surface; and a thin stator vane integrally formed tolink between the outer band and the inner band, the thin stator vanehaving a suction surface having an identical shape to a suction surfaceof the thick stator vane and a smooth pressure surface approximating toa pressure surface of the thick stator vane, the thin stator vane beingconfigured to be thinner than the thick stator vane so that the pressuresurface comes near to the suction surfaces.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic drawing of a gas turbine engine in accordance withan embodiment of the present invention

FIG. 2 is a partial cross sectional view of a low pressure turbine in ajet engine in accordance with the embodiment of the present invention.

FIG. 3 is a partial front view of a turbine nozzle at a first stage inaccordance with the embodiment of the present invention.

FIG. 4 is a front view of a turbine nozzle segment in accordance withthe embodiment of the present invention.

FIG. 5 is a drawing taken along a V-V line in FIG. 3.

BEST MODE FOR CARRYING OUT THE INVENTION

To explain the present invention in more detail, an embodiment will bedescribed herein after with proper reference to the drawings. Meanwhile,in these drawings, “FF” indicates a forward direction, “FR” indicates arearward direction, and “S” indicates spanwise directions.

As shown in FIG. 1 and FIG. 2, a low pressure turbine 1 in accordancewith the embodiment of the present invention is applied to a jet engine3 as an example of a gas turbine engine, and is provided with a lowpressure turbine case 5.

In the low pressure turbine case 5 a plurality of stages of turbinedisks 7, 9 11 are arranged to leave intervals in its fore and aftdirections/and the plurality of stages of the turbine disks 7, 9, 11 areintegrally linked with each other and rotatable around an engine axialcenter C. Further, at outer peripheral portions of the respective stagesof the turbine disks 7, 9, 11, a plurality of turbine blade 13, 15 17are respectively provided here, the plurality of turbine disks 7, 9, 11are integrally linked with rotors of a not-shown low pressure compressorand rotors of not-shown fans.

In the low pressure turbine case 5, a plurality of stages of turbineshrouds 19 21, 23 for suppressing overheat of the low pressure turbinecase 5 are arranged so as to respectively enclose the turbine blades 13,15 17 of correspondent stages. Further, the respective stages of theturbine shrouds 19, 21, 23 are respectively provided with honeycombmembers 25, 27, 29 capable of allowing tip portions of the turbineblades 13, 15, 17 of correspondent stages. Here, the respective stagesof turbine shrouds 19, 21, 23 are respectively segmented

In the low pressure turbine case 5 a plurality of stages of turbinenozzles 31, 33, 35 are arranged so as to alternate with the plurality ofstages of the turbine disks 7 9, 11 to leave intervals in the fore andaft directions. Here, the respective stages of the turbine nozzles 31,33, 35 are respectively segmented.

Therefore, as the plurality of stages of the turbine disks 7, 9, 11integrally rotate by expansion of high-temperature gas from a not-showncombustor, the low pressure turbine 1 obtains driving force and makesthe rotors of the low pressure compressor and the rotors of the fansintegrally rotate to drive the compressor and the fans.

As shown in FIG. 3 and FIG. 4, the turbine nozzle 31 of the first stageis applied to a low pressure turbine 1 as mentioned above, and iscomposed of plurality of turbine nozzle segments 37 arranged in acircle. Configurations of the respective turbine nozzle segments 37 areas follows.

Specifically, the turbine nozzle segment 37 is provided with an outerband 39 of an arc shape, an inner band 41 of an arc shape providedopposed to the outer band 39. Between the outer band 39 and the innerband 41, a thick stator vane 43 is integrally formed to link therebetween, and the thick stator vane 43 is disposed at one ends of thebands 39, 41. Further, between the outer band 39 and the inner band 41,two thin stator vanes 45 are integrally formed to link therewith.

Here, as shown in FIG. 5, each of the thin stator vanes 45 have asuction surface 45 a having the same shape as a suction surface 43 a ofthe thick stator vane 43, and a pressure surface 45 b having a smoothshape approximating to a shape of a pressure surface 43 b of the thickstator vane 43. The thin stator vanes 45 are configured to be thinnerthan the thick stator vane 43 so that the pressure surfaces 45 b comenear to the suction surfaces 45 a.

Further, to any turbine nozzle segment 37′ among the plurality ofturbine nozzle segments 37, the following configurations are furtheradded.

More specifically, as shown in FIG. 5, FIG. 2, and FIG. 3, in the thickstator vane 43, an insertion hole 49 to which a probe 47 for measuringtemperature of the hot gas is insertable from the side of the outer band39 is formed by electric spark machining or such, the insertion hole 49is disposed at a maximum thickness portion of the thick stator vane 43,and a tip end portion of the insertion hole 49 extends to the vicinityof the central portion in the spanwise directions S in the thick statorvane 43. Further, at the vicinity of the central portion in the spanwisedirections S in the pressure surface 43 b of the thick stator vane 43,the inlet hole 51 communicating with the insertion hole 49 is formed.And, at the vicinity of the central portion in the spanwise directions Sin the suction surface 43 a of the thick stator vane 43, an outlet hole53 communicating with the insertion hole 49 is formed. Here, the inlethole 51 and the outlet hole 53 are disposed on an identical line but arenot necessarily disposed on the identical line.

Meanwhile, the probe 47 is electrically connected with a controller 57via an amplifier 55 fixed on the low pressure turbine case 5.

Next, operations of the embodiment of the present invention will bedescribed hereinafter.

Because the insertion hole 49 to which the probe 47 is insertable fromthe side of the outer band 39 into the thick stator vane 43 is formed inthe turbine nozzle segment 37′ and the inlet hole 51 communicating withthe insertion hole 49 is formed on the pressure surface 43 b of thethick stator vane 43 in the turbine nozzle segment 37′, the temperatureof the hot gas flowing into the inlet hole 51 can be measured by theprobe 47 during operation of the jet engine without arranging rakesextending in the radial direction of the jet engine in the gas flow pathof the jet engine or forming the stator vanes 43, 45 of the turbinenozzle segment 37′ a hollow structure to be a hollow structure bycasting. Meanwhile, the controller 57 controls the fuel flow rate andsuch based on the measured data.

Further, because the outlet hole 53 communicating with the insertionhole 49 is formed on the suction surface 43 a of the thick stator vane43 in the turbine nozzle segment 37′, the inlet hole 51 and the outlethole 53 communicates with each other via the insertion hole 49 and hencefluidity of the hot gas flowing in the inlet hole 51 can be assured.

Further, because the thin stator vane 45 in each of the turbine nozzlesegments 37 is configured to be thinner than the thick stator vane 43 sothat the pressure surface 45 b comes closer to the suction surface 45 a,reduction in weight of the turbine nozzle segment 37, in other words,reduction in weight of the turbine nozzle 31, can be achieved.

Moreover, because each thin stator vane 45 of the respective turbinenozzle segments 37 has the suction surface 45 a having the same shape asthe suction surface 43 a of the thick stator vane 43, even if each thickstator vane 43 and each thin stator vane 45 of the respective turbinenozzle segments 37 are not the same in shape, decline in aerodynamicperformance can be prevented. Further, because each stator vane 45 ofthe respective turbine nozzle segments 37 has the pressure surface 45 bhaving the smooth shape approximating to the shape of the pressuresurface 43 b of the thick stator vane 43, each thick stator vane 43 andeach thin stator vane 45 of the respective turbine nozzle segments 37are not the same in shape, total pressure loss of the plurality ofstator vanes 43, 45 can be moderated.

In accordance with the best mode as mentioned above, because it ispossible to measure temperature of the hot gas flowing into the in lethole 51 by means of the probe 47 inserted into the insertion hole 49during operation of the jet engine without arranging rakes extending inradial directions in the gas flow path of the jet engine, or shapingstator vanes 43, 45 of the turbine nozzle segment 37′ into hollowstructures by casting, with reducing production cost of the turbinenozzle 31, reduction in weight of the jet engine can be achieved byavoiding elongation of the gas turbine engine in the axial direction aswell as engine performance of the gas turbine engine can be improved bydecreasing number of parts which cause vibration excitation source andair resistance in the gas flow path.

Moreover, because the inlet hole 51 and the outlet hole 53 communicatewith each other via the insertion hole 49 and fluidity of the hot gasflowing into the inlet hole 51 can be assured fluctuation of themeasured temperature of the hot gas is suppressed so as to assure highlyaccurate measurement of the hot gas by means of the probe 47.

Further, even if each thick stator vane 43 and each thin stator vane 45of the respective nozzle segments 37 are not identical in shape, becausetotal pressure loss of the stator vanes 43, 45 is moderated andreduction in weight of the turbine nozzle 31 is achieved, weightreduction of the jet engine can be promoted.

Although the present invention has been described above by reference tocertain preferred embodiments, the scope of the right included in theinvention is not limited to these embodiments. Modifications of theembodiments, in which for example, instead of the insertion hole 49 towhich the probe 47 for being applied to measuring temperature of hot gasis insertable being formed in the interior of the thick stator vane 43an insertion hole to which another probe for measuring pressure of thehot gas is insertable, will occur or such to embody the invention.

The entire contents of the patent application No. 2004-130210 filed withthe Japan Patent Office on Apr. 26, 2004 are made to be incorporatedinto the contents of the present application by reference.

1. A turbine nozzle applied to a turbine of a gas turbine engine, theturbine nozzle comprising a plurality of turbine nozzle segmentsarranged in a circle: each of the turbine nozzle segments comprising; anouter band of an arc shape, an inner band of an arc shape provided toopposed to the outer band, a thick stator vane integrally formed to linkbetween the outer band and the inner band, and a thin stator vaneintegrally formed to link between the outer band and the inner band, thethin stator vane having a suction surface having an identical shape to asuction surface of the thick stator vane and a smooth pressure surfaceapproximating to a pressure surface of the thick stator vane, the thinstator vane being configured to be thinner than the thick stator vane sothat the pressure surface comes near to the suction surfaces, theturbine nozzle characterized in that; an insertion hole to which a probefor measuring a temperature or a pressure of a hot gas is insertablefrom a side of the outer band is formed in the thick stator vane of anyturbine nozzle segment of the plurality of turbine nozzle segments, andan inlet hole communicating with the insertion hole is formed on thepressure surface of the thick stator vane of said any turbine nozzlesegment.
 2. The turbine nozzle as set forth in claim 1, characterized inthat an outlet hole communicating with the insertion hole is formed onthe suction surface of the thick stator vane of said any turbine nozzlesegment.
 3. A turbine nozzle segment as a segment of a turbine nozzleapplied to a turbine of a gas turbine engines the turbine nozzle segmentcharacterized by comprising: an outer band of an arc shape; an innerband of an arc shape provided to opposed to the outer band, a thickstator vane integrally formed to link between the outer band and theinner band, wherein an insertion hole to which a probe for measuring atemperature or a pressure of a hot gas is insertable from a side of theouter band is formed in the thick stator vane, and an inlet holecommunicating with the insertion hole is formed on the pressure surface;and a thin stator vane integrally formed to link between the outer bandand the inner band, the thin stator vane having a suction surface havingan identical shape to a suction surface of the thick stator vane and asmooth pressure surface approximating to a pressure surface of the thickstator vane, the thin stator vane being configured to be thinner thanthe thick stator vane so that the pressure surface comes near to thesuction surfaces.
 4. The turbine nozzle segment as set forth in claim 3,characterized in that an outlet hole communicating with the insertionhole is formed on the suction surface of the thick stator vane.
 5. Aturbine comprising the turbine nozzle segment as set forth in claim 1 orclaim
 2. 6. A gas turbine engine comprising the turbine as set forth inclaim 5.